NASA GIVES GO-AHEAD FOR AIRBORNE OBSERVATORY

  By BRIAN BERGER
  Space News Staff Writer
  
  WASHINGTON - NASA has given the final go-ahead for a $350 million
  airborne astronomy lab slated to take to the skies in 2002.
  
  The Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint
  effort between the NASA and the German Aerospace Center, has been in
  development since 1997.
  
  A NASA review board recently gave final approval to the airborne
  observatory's design, clearing the way for the SOFIA team to finish
  refurbishing a commercial airliner and equipping it with a 2.5-meter
  telescope.
  
  Once finished, the airplane--a Boeing 747SP that NASA bought used from
  United Airlines for $12 million--will fly three or four times a week
  out of NASA's Ames Research Center, Moffett Field, Calif., on 8-10 hour
  nighttime sorties to observe the infrared universe.
  
  SOFIA is funded by NASA's Office of Space Science, with contributions
  from the German Aerospace Center.
  
  SOFIA program officials said the flying observatory offers several
  advantages over ground- and space-based telescopes.
  
  Because most infrared energy is blocked by water vapor in Earth's
  atmosphere, even very large telescopes positioned high atop mountains
  can make only limited observations of the otherwise invisible universe.
  
  But SOFIA, capable of flying at altitudes of 12,000 to 13,500 meters,
  will cruise above all but about 1 percent of Earth's infrared-absorbing
  water vapor, giving astronomers a good view of such astronomical
  phenomena as the formation of new solar systems and the death of stars.
  
  SOFIA also is expected to make large contributions to the emerging field
  of astrobiology. Program scientists said the observatory will be a boon
  to astronomers interested in studying high concentrations of pre-biotic
  molecules such as amino acids and hydrocarbons - the so-called building
  blocks of life - sometimes found swirling through dusty regions of space
  considered ripe for planetary formation.
  
  "SOFIA will be the prime instrument for the next 10 to 20 years for
  studying how molecules form in space," said Eric Becklin, lead scientist
  for SOFIA.
  
  SOFIA is a follow-on to NASA's Kuiper Airborne Observatory, a C-141
  transport plane equipped with a 1-meter telescope that the space agency
  operated from 1971 to 1995. Kuiper is credited with the 1977 discovery
  of a ring system around the planet Uranus.
  
  U.S. and German program officials said SOFIA will continue to make
  valuable contributions to the field of infrared astronomy long after the
  European Space Agency's Far Infrared Space Telescope and NASA's Next
  Generation Space Telescope are launched later this decade.
  
  Alois Himmes, German Aerospace Center project manager for the SOFIA
  telescope, said a space-based telescope with a comparable optic would
  provide a better view of the infrared universe. "It cannot do more than
  a satellite," he said. "But it's not as expensive."
  SOFIA's projected development cost is $350 million, according to
  Christopher Wiltsee, SOFIA project manager at Ames Research Center.
  
  The bulk of that money--about $280 million--will come from NASA and
  pay for refurbishing and modifying the 747SP and building a mission
  control and simulation center at Ames, he said. NASA bought the aircraft
  in 1997 from Chicago-based United Airlines Inc., which will maintain and
  operate the plane under a contract from the Universities Space Research
  Association, Columbia, Md., the SOFIA prime contractor, Wiltsee said.
  
  NASA plans to fly SOFIA for 20 years and has budgeted about $40 million
  a year for operations, Wiltsee said.
  
  When SOFIA takes to the skies in 2002, it will be equipped with 10
  science instruments, more than any space-based observatory so far, he
  said. SOFIA's extreme mobility--the 747SP was built to carry passengers
  across the Pacific Ocean--is another one of its strengths, Wiltsee
  said.
  
  Since spacecraft are literally stuck on orbit, they cannot easily be
  repositioned to observe such events as a supernova or the occultation of
  a planet by a star, he said.
  
  "Something ephemeral could take place, like a supernova," he said. "If
  you have to go to the Southern Hemisphere to get the best view, SOFIA
  can be there right away," he said.
  
  Another advantage SOFIA has over space-based telescopes is its
  similarity to ground-based observatories. "Like a ground based tele
  scope, you can install the latest instruments as they become available,"
  Wiltsee said.

  About 10 percent of SOFIA's annual budget will be devoted to developing
  new instruments, he said, noting NASA plans to issue requests for
  instrument proposals every two or three years.